Apparatuses for unwinding rolls of cloth supported between two rolls have been known as dewinders, and it is generally recognized that unwinding a roll of cloth in open width or at least with minimal folds so as to be considered in open width presents more problems than winding the cloth in the first instance. In the textile industry, it is often desirable to unwind rolls of cloth as for inspection or for further processing as in dyeing, or otherwise, finishing the cloth. The fabric tends to loosen in the outer layers causing the fabric to bunch up at the nip or contact point between the fabric roll and the driven roll or rolls. Similar problems are presented in the paper industry where rolls of paper are unwound. Other webs which are being unwound in open width present analogous problems.
A center wind unwinder is illustrated in U.S. Pat. No. 3,900,063 while a surface unwinder utilizing a belt forming a cradle between two rolls for accommodating a cloth roll is illustrated in Austrian Patent No. 228,151 of 1963. This Austrian Patent illustrates structure utilized in attempting to solve a belt tracking problem by utilizing endless V-shaped belt portions carried across the underside of the cradle forming belt with corresponding grooves in the rolls carrying the belt. It has been found, however, that such structures are ineffective in dealing with heavier cloth rolls which often weigh as much as 4,400 pounds and are 50 inches in diameter. An application of the belt and cradle arrangement to the paper industry is illustrated in U.S. Pat. No. 2,977,058. Other attempts to provide dewinders utilizing a cradle arrangement forming belt have included other uses of V-belts spaced longitudinally across the back of the cradle forming belt but such arrangements have been practical only with very light rolls and do not effectively solve the problem of guiding the cradle forming belt.
Accordingly, it is an important object of this invention to provide a dewinder utilizing surface unwinder principles and a cradle forming belt extended between spaced level rolls which provide guide means for assuring proper tracking of the cradle forming belt together with effective means for doffing an empty core roll and placing a full roll of cloth and the like upon the cradle forming belt for unwinding.
Another important object of the invention is to provide guide means for maintaining the tubular roll in proper transverse alignment upon the belt.